Comments

There are several Xanthoria spp., e.g. X. fulva (K+ strong wine/red) which form diffuse colonies on rock. Also should consider Candelaria and Candelariella, both K+ weak reddish or K-. It will help to get a good close look at it to see if there are intact lobes, and whether they have upper and lower cortex, and where the granules are formed (under lobes? on margins? at tips?). Also check for darker orange “pimples” (pycnidia, likely sign of Caloplaca although not necessarily) and of course apothecia (all three can produce apothecia).